feat: add request size limit plugin

plugins/wasm-go/extensions/request-size-limit/README.md

@@ -0,0 +1,21 @@
+# 功能说明
+`request-size-limit` 插件实现了限制请求 body 大小的作用，可以用于防止请求 body 过大的请求对网关及上游服务造成影响。
+
+# 配置字段
+
+| 名称          | 数据类型   | 填写要求                                        | 默认值 | 描述             |
+|-------------|--------|---------------------------------------------|-----|----------------|
+| requestSize | string | 需填写允许的请求体最大大小，单位为 B、KB、MB 或 GB。例如 1KB，2MB 等 | 1MB | 配置允许通过的请求体最大大小 |
+
+# 配置示例
+
+## 限制请求 body 超过 5B 的请求
+
+```yaml
+requestSize: 5B
+```
+配置完毕之后，下列请求将被禁止访问：
+
+```bash
+curl -d "123456" http://example.com
+```

plugins/wasm-go/extensions/request-size-limit/VERSION

@@ -0,0 +1 @@
+1.0.0

plugins/wasm-go/extensions/request-size-limit/go.mod

@@ -0,0 +1,19 @@
+module github.com/alibaba/higress/plugins/wasm-go/extensions/request-size-limit
+
+go 1.19
+
+replace github.com/alibaba/higress/plugins/wasm-go => ../..
+
+require (
+	github.com/alibaba/higress/plugins/wasm-go v0.0.0
+	github.com/tetratelabs/proxy-wasm-go-sdk v0.19.1-0.20220822060051-f9d179a57f8c
+	github.com/tidwall/gjson v1.14.3
+)
+
+require (
+	github.com/google/uuid v1.3.0 // indirect
+	github.com/magefile/mage v1.14.0 // indirect
+	github.com/tidwall/match v1.1.1 // indirect
+	github.com/tidwall/pretty v1.2.0 // indirect
+	github.com/wasilibs/nottinygc v0.3.0 // indirect
+)

plugins/wasm-go/extensions/request-size-limit/go.sum

@@ -0,0 +1,18 @@
+github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
+github.com/google/uuid v1.3.0 h1:t6JiXgmwXMjEs8VusXIJk2BXHsn+wx8BZdTaoZ5fu7I=
+github.com/google/uuid v1.3.0/go.mod h1:TIyPZe4MgqvfeYDBFedMoGGpEw/LqOeaOT+nhxU+yHo=
+github.com/magefile/mage v1.14.0 h1:6QDX3g6z1YvJ4olPhT1wksUcSa/V0a1B+pJb73fBjyo=
+github.com/magefile/mage v1.14.0/go.mod h1:z5UZb/iS3GoOSn0JgWuiw7dxlurVYTu+/jHXqQg881A=
+github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
+github.com/stretchr/testify v1.8.0 h1:pSgiaMZlXftHpm5L7V1+rVB+AZJydKsMxsQBIJw4PKk=
+github.com/tetratelabs/proxy-wasm-go-sdk v0.19.1-0.20220822060051-f9d179a57f8c h1:OCUFXVGixHLfNjg6/QYEhv+jHJ5mRGhpEUVFv9eWPJE=
+github.com/tetratelabs/proxy-wasm-go-sdk v0.19.1-0.20220822060051-f9d179a57f8c/go.mod h1:5t/pWFNJ9eMyu/K/Z+OeGhDJ9sN9eCo8fc2pyM/Qjg4=
+github.com/tidwall/gjson v1.14.3 h1:9jvXn7olKEHU1S9vwoMGliaT8jq1vJ7IH/n9zD9Dnlw=
+github.com/tidwall/gjson v1.14.3/go.mod h1:/wbyibRr2FHMks5tjHJ5F8dMZh3AcwJEMf5vlfC0lxk=
+github.com/tidwall/match v1.1.1 h1:+Ho715JplO36QYgwN9PGYNhgZvoUSc9X2c80KVTi+GA=
+github.com/tidwall/match v1.1.1/go.mod h1:eRSPERbgtNPcGhD8UCthc6PmLEQXEWd3PRB5JTxsfmM=
+github.com/tidwall/pretty v1.2.0 h1:RWIZEg2iJ8/g6fDDYzMpobmaoGh5OLl4AXtGUGPcqCs=
+github.com/tidwall/pretty v1.2.0/go.mod h1:ITEVvHYasfjBbM0u2Pg8T2nJnzm8xPwvNhhsoaGGjNU=
+github.com/wasilibs/nottinygc v0.3.0 h1:0L1jsJ1MsyN5tdinmFbLfuEA0TnHRcqaBM9pDTJVJmU=
+github.com/wasilibs/nottinygc v0.3.0/go.mod h1:oDcIotskuYNMpqMF23l7Z8uzD4TC0WXHK8jetlB3HIo=
+gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=

plugins/wasm-go/extensions/request-size-limit/main.go

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+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package main
+
+import (
+	"errors"
+	"github.com/alibaba/higress/plugins/wasm-go/pkg/wrapper"
+	"github.com/tetratelabs/proxy-wasm-go-sdk/proxywasm"
+	"github.com/tetratelabs/proxy-wasm-go-sdk/proxywasm/types"
+	"github.com/tidwall/gjson"
+	"regexp"
+	"strconv"
+	"strings"
+)
+
+func main() {
+	wrapper.SetCtx(
+		"request-size-limit",
+		wrapper.ParseConfigBy(parseConfig),
+		wrapper.ProcessRequestBodyBy(onHttpRequestBody),
+	)
+}
+
+type RequestSizeLimitConfig struct {
+	requestSize int64
+}
+
+func parseConfig(json gjson.Result, config *RequestSizeLimitConfig, log wrapper.Log) error {
+	sizeStr := json.Get("requestSize").String()
+	sizeStr = strings.TrimSpace(sizeStr)
+	re := regexp.MustCompile("^([+\\-]?\\d+)([a-zA-Z]{0,2})$")
+	submatchs := re.FindStringSubmatch(sizeStr)
+	if len(submatchs) == 0 {
+		config.requestSize = 1024 * 1024
+		return nil
+	}
+	amount, _ := strconv.ParseInt(submatchs[1], 10, 64)
+	unitStr := submatchs[2]
+	if len(unitStr) == 0 {
+		config.requestSize = amount
+	} else {
+		unitSizeMap := map[string]int64{
+			"B":  1,
+			"KB": 1024,
+			"MB": 1024 * 1024,
+			"GB": 1024 * 1024 * 1024,
+		}
+		unit, ok := unitSizeMap[unitStr]
+		if !ok {
+			return errors.New("Invalid unit size: " + unitStr)
+		}
+		config.requestSize = amount * unit
+	}
+	return nil
+}
+
+func onHttpRequestBody(ctx wrapper.HttpContext, config RequestSizeLimitConfig, body []byte, log wrapper.Log) types.Action {
+	if int64(len(body)) > config.requestSize {
+		proxywasm.SendHttpResponse(413, nil, []byte("The request body is too large"), -1)
+		return types.ActionContinue
+	}
+	return types.ActionContinue
+}